The subject matter disclosed herein relates to a heat exchanger and, more particularly, to a shell and tube heat exchanger.
Heating and cooling systems, such as HVAC and refrigeration systems, typically employ various types of heat exchangers to provide heating and cooling. These heat exchangers often include shell and tube or tube in tube heat exchangers. In each case, heat transfer usually occurs between fluids that are directed to flow in close proximity to one another and in a closely coupled heat transfer interaction with one another.
For example, in a shell and tube heat exchanger, a shell forms an exterior surface of a vessel into which refrigerant vapor is introduced. Water is then directed through water tubes extending through the vessel such that heat transfer occurs between the refrigerant and the water. In another example, refrigerant may be directed through the tubes, while water or other heat transfer media, such as ethylene glycol or propylene glycol, is directed through the space between the tubes and the heat exchanger outer shell.
Shell and tube heat exchangers typically represent about 50% of the cost of water cooled chillers and often determine the required refrigerant amount and the unit footprint, both of which tend to change over time in response to constantly rising energy efficiency demands that typically increase the size limitations and cost of shell and tube heat exchangers.